Apparatus for treating metal parts



Nov. 4, 1958 c. 1.. JOY

' APPARATUS FOR TREATING METAL PARTS 5 Sheets-Sheet 1 Filed June 6. 19558 r w/r m m H A Z a p Y B \v c. L. JOY 2,859,029 APPARATUS 'FOR TREATINGMETAL PARTS 5 Sheets-Sheet 2 Nov. 4, 1958 Filed June 6. 1955 'Nov.4,1958 GEL. Jo 2,859,029

APPARATUS FOR TREATING METAL PARTS Filed June 6. 1955 I 5 Sheets-Sheet 3Nov. 4, 1958 c. L. JOY

APPARATUS FOR TREATING METAL PARTS Filed June 6. 1955 5 Sheets-Sheet 4Ill h L m 2w w MH L H m INVENTOR.

ATTOR/VfYS m at! Z. Jar WW WW Nov. 4, 1958 c. L. JOY 2,859,029

APPARATUS FOR TREATING METAL PARTs Filed June 6. 1955 5 Sheets-Sheet 5 Il l IN V EN TOR.

v Cum-M2- 1 Jo) United States Patent a "ice 2,859,029 APPARATUS FORTREATING METAL PARTS Clarence L. Joy, Detroit, Mich., assignor toHolcroft & Company, Detroit, Mich., a corporation of MichiganApplication June 6, 1955, Serial No. 513,435

4 Claims. (Cl. 266-4) This invention relates to an improved method andapparatus for treating metal parts, and is a continuation-inpart of myco-pending application for Method and Apparatus for Treating MetalParts, Serial No. 166,287, filed June 5, 1950, now U. S. Patent No.2,716,989.

In treating certain metal parts such for example as cast iron parts, itis customary to anneal or heat the metal parts to the stress relievingtemperature of the metal and to clean the parts by a descaling ordesanding operation. There are several current processes foraccomplishing the two above operations, but in each process theannealing and cleaning operations are performed at the same time bysubmerging the metal parts into a fused alkali bath. In following eitherof these processes, it is essential to not only heat the bath to therequired stress relieving temperature of the parts, but to also allowthe metal parts to remain in the bath for a sufficient time to properlyheat the parts. Thus tanks of some considerable size were necessary, andcare had to be taken to keep the temperature of the bath below thetemperature at which decomposition of the salt takes place.

With the above in view, it is an object of this invention to heat treator anneal and clean the metal parts in steps which although separate arenevertheless continuous. In accordance with this invention the parts areheated to the desired temperature within a furnace, and are advanceddirectly from the furnace into the cleaning or fused alkali bath. Thusheat treating of the parts is accomplished prior to introducing the sameto the cleaning bath, and the parts are at elevated temperatures whensubmerged into the bath. As a result no time need be allowed in thecleaning bath for heating the parts and the cleaning operation is notonly expedited, but the size of the tank for the bath may be materiallyreduced.

Cleaning processes embodying fused alkali baths ordinarily require theparts to be introduced into several rinsing and acid baths. templates aunique apparatus for automatically handling the parts so that theoperation is continuous regardless of the number of baths provided.

The foregoing as well as other objects will be made more apparent asthis description proceeds, especially when considered in connection withthe accompanying drawings, wherein:

Figure 1 is a side elevational view partly in section of a heat treatingfurnace forming a part of the apparatus of the present invention;

Figure 2 is a fragmentary top plan view of the furnace shown in Figure1;

Figure 3 is a cross-sectional View taken substantially on the line 3-3of Figure 1;

Figure 4 is a semi-diagrammatic side elevational view of the metalcleaning part of the apparatus;

Figure 5 is a top plan view of the construction shown in Figure 4;

Figure 6 is a cross-sectional view taken on the line 66 of Figure 4;

To this end the invention conthese trays into the furnace.

Patented Nov. 4, 1958 the apparatus shown in Figure 4.

For the purpose of illustrating the present invention, it will beassumed that the apparatus to be presently described serves to anneal orheat treat metal castings to the stress relieving temperature of themetal, and also to descale, desand or otherwise clean the metalcastings. It will, ofcourse, be understood as this description proceedsthat the apparatus and particularly various parts of the apparatus maybe employed for heat treating and/ or cleaning metal parts other thancastings.

In general, metal parts are supported on trays 20 and the trays areadvanced through a furnace 21 to a cleaning unit 22. During advancementof the trays 20 through the furnace 21', the metal articles carried bythe trays are heated to the stress relieving temperature of the metalfrom which the articles are formed. The heated articles delivered fromthe furnace are conveyed directly to the cleaning unit 22, and aresuccessively submerged into various baths to be presently described indetail.

With' the above in view, reference is made more in detail to thedrawings. The furnace 21 shown in Figures 1 to 3 inclusive of thedrawings embodies an elongated tunnel 23 open at both ends and heated inany suitable manner, such for example, as by gas-fired burners not shownherein; The entrant end 24 of the furnace is normally closed by a door25, and the delivery end 26 is normally closed by adoor 27. The twodoors are suitably supported for vertical sliding movement and arerespectively operated by fluid motors 28. In accordance withconventional practice, the fluid motors 28 are supported with thecylinders extending vertically, and the pistons are connected toflexible cables 29. The flexible cables 29 extend upwardly over pulleys30 and are secured to the pulleys 30. Upon reference to Figure 2 of thedrawings, it will be noted that the pulleys 30 are respectively securedto cross shafts 31 which are journalled on suitable frame structure 32at the top of the furnace. The opposite ends of the doors arerespectively connected to cables 33, and these cables extend upwardlyover pulleys 34 on the respective shafts 31. The upper ends of thecables are secured to the pulleys 34 so that rotation of the shafts bythe fluid motors 28 raises the doors to their open positions. The twodoors 25 and 27 move by gravity to their closed positions when the fluidmotors are exhausted.

The hearth of the furnace comprises a plurality of laterally spacedlongitudinally extending rails 35, and the rollers 36 are supported onthe rails in spaced relation to each other longitudinally of the rails.The rollers 36 provide an anti-friction support for the trays 20, andenable the same to be readily advanced through the furnace.

It will be noted from Figures Land 2 of the drawings that a loadingplatform 37 is supported at the front end of the furnace. The loadingplatform 37 is provided with longitudinally extending rails 38, which ineifect, form continuations of the rails 35 and provide supports for aplurality of rollers 39.

The rollers 39 support a series of trays 20 beyond the entrant end ofthe furnace, and these trays are successively moved into the furnace bypushers 40. Each pusher 40 hasa fluid motor 41 supported beneath therollers 39 with thecylinder in a horizontal position, and having thepiston connected to a head 42. Suitable dogs 43 are respectivelypivotally connected to the heads in positions'to engage the front edgesof the trays supported immediately adjacent the entrant opening 24 tomove The succeeding trays are successively advanced to positionsimmediately in rear -adjacent the delivery opening 26 in the furnace.

of the dogs 43 by dogs 44. The dogs 44 are pivoted to slides 45, andrespectively engage the front edges of adjacent trays 20. An additionaldog 46 is pivoted to each slide 45 in rear of the dog 44, and thepurpose of this dog is to advance the adjacent tray to the rear side ofthe corresponding dog 44.

It follows from the foregoing that when the heads 42 are movedrearwardly by the respective fluid motors 40, the dogs 43 move theadjacent trays into the furnace 21 through the entrant opening 24. Atthe same time the dogs 44 move adjacent trays over the dogs 43 toposition the trays at the rear sides of the dogs 43 where they may beengaged by the dogs 43 during the next cycle of operation. Also at thesame time the dogs 46 move the adjacent trays 20 over the dogs 44 topositions at the rear sides of the latter dogs, so that these trays mayalso be engaged by the dogs 44 during the next cycle of operation.

It will be noted from Figure 1 of the drawings that when the trays 20assume positions within the furnace 21, adjacent side edges of the trayscontact one another, so that each time the dogs 43 push trays 20 intothe furnace, all of the trays in the furnace are advanced a distanceapproximating the length of one tray. It will, of course, be understoodthat when this operation takes place, both doors 25 and 27 are in theiropen positions in order to not only enable trays from the loadingplatform to be inserted into the furnace, but to also permit the traysadjacent the delivery opening 26 to be moved out of the furnace.

The trays within the furnace adjacent the delivery opening 26 are movedout of the furnace by slides in the form of racks 48 shown particularlyin Figures 1, 2 and 4. The rear ends of the racks are respectivelyengaged by gears 49 secured in proper spaced relationship on a crossshaft 50 which is connected at one end to a source of power 51. Thefront ends of the racks project into the rear end of the furnace belowthe door 27 and below the plane of the trays in the furnace. Suitabledogs 52 are respectively pivotally connected to the racks 48 inpositions to engage shoulders at the rear edges of the trays 20 as thelatter assume positions Thus rearward movement of the racks 48 enablesthe dogs 52 to advance the trays through the furnace delivery opening 26to the position indicated by the numeral 53 in Figure 1 of the drawings.The trays 20 at the position 53 are engaged at the front edges thereofby dogs 54 respectively pivotally supported on the racks 48 adjacent therear ends of the latter. Upon rearward movement of the racks 48 by thepower means 51, the dogs 54 advance the trays at the position 53 to thecleaning unit 22.

Cleaning unit Upon reference to Figure 4 of the drawings, it will benoted that the cleaning unit 22 comprises a plurality of tanks spacedfrom each other in a row extending in the direction of advancement ofthe trays 20 through the furnace. The first tank 55 is adapted tocontain a fused alkali bath, and this bath is maintained at the propertemperature for cleaning the parts by heating units 56. The nextadjacent tank 57 contains a bath comprising preferably water, and thefollowing tank 58 contains an acid bath which serves to remove any saltfrom the metal parts remaining thereon after being subjected to thewater bath in the tank 57. The acid is removed from the metal parts by afourth bath contained in a tank 59, and a lubricant or rust preventiveis applied to the articles by submerging the latter into a bath ofsoluble oil contained in the last tank 60 in the row.

The article supporting trays 20 are submerged into the baths byelevators 61, 62, 63, 64 and 65. These elevators are respectivelysupported above the tanks 55, 57, 58, 59 and 60 for vertical movementinto and out of the baths. The elevators are operated as a unit by twopairs of fluid motors 66 and 67 supported above the cleaning unit onsuitable frame 68.

As shown in Figure 6 of the drawings, the opposite ends of the elevator64 are connected to the lower ends of flexible cables 69 having theupper ends reeved over pulleys 70. From the pulleys 70 the cables 69extend forwardly, and are respectively connected to the pistons of thepair of fluid motors 66. The pulleys 70 are secured to a cross shaft 71,which in turn, is journalled on the frame structure 68, so that movementof the pistons in the fluid motors rearwardly rotates the pulleys 70 inthe direction of the arrow 72 and causes the elevator 64 to movedownwardly into the tank 59.

The elevator 65 is connected at opposite ends to flexible cables 73, andthese cables are secured at their upper ends to pulleys 74. The pulleys74 are secured to a cross shaft 75 which is journalled on the framestructure 68 and has a pulley 76 secured thereto. The pulley 76 isconnected 'by a belt 77 to a pulley 78 fixed to the shaft 71, so thatrotation of the shaft 71 in the direction of the arrow 72 by the fluidmotors 66 imparts rotation to the shaft 75 in a'corresponding directionto lower the elevator 65 into the tank 60.

The elevator 63 is connected at opposite ends to flexible cables 79, andthe upper ends of the cables are secured to pulleys 80. The pulleys 80are fixed to a shaft 81 also journalled on the framing 68 and having apulley 82 secured thereto. The pulley 82 is connected by a belt 83 tothe pulley 78 on the shaft 71, and as a consequence, the elevator 63 islowered into the tank 58 when the shaft 71 is rotated in the directionof the arrow 72. Of course, it will be understood that movement of thepistons in the fluid motors 66 in a forward direction raises theelevators 63, 64 and 65 as a unit.

The elevator 61 is connected at opposite ends to flexible cables 84having the upper ends respectively fixed to pulleys 85 secured to across shaft 86. Pulleys 87 are secured to the shaft 86, and arerespectively connected to flexible cables 88. The cables 88 extendrearwardly from the pulleys 87, and are connected to the fluid motors ofthe pair 67. The shaft 86 also has a pulley 89 secured thereto, and thispulley is connected by a belt 90 to a pulley 91 secured to a cross shaft92. The cross shaft 92 is journalled on the frame 68 directly above theelevator 62, and a pair of pulleys 93 are secured to the shaft 92. Thepulleys 93 are respectively connected to opposite ends of the elevator62 by flexible cables 94.

With the above construction, it will be noted that forward movement ofthe pistons in the fluid motors 67 provides for rotation of the shafts86 and 92 in the direction of the arrows shown in Figure 4 of thedrawings. As a result the elevators 61 and 62 are re pectively loweredinto the tanks 55 and 57. Rearward movement of the pistons in the fluidmotors 67 rotates the shafts 86 and 92 in the opposite direction, andcauses the elevators 61 and 62 to return to their uppermost positionsshown in Figure 4 of the drawings. The two pairs of fluid motors areoperated as a unit so that all of the elevators are simultaneously movedinto and out of their respective tanks, depending upon the direction ofmovement of the pistons in the fluid motors. When the elevators are intheir raised positions shown in Figure 4 of drawings, the top surfacesthereof lie in a common plane which includes a tray supporting surface95. The tray support 95 extends between adjacent elevators, and is inthe form of a grating as shown in Figure 5 of the drawings. In fact itwill also be noted from Figure 5 that the tray supporting surface ofeach elevator is also in the form of a grating 96 arranged to form acontinuation of the grating 95 when the elevators are in their raisedpositions.

The trays 20 leaving the delivery end of the furnace 21 are successivelypositioned on the elevators 61 to 65 inclusive by a propelling device97. The propelling device 97 comprises a rectangular frame having siderails 98 secured in lateral spaced relationship by cross members 99. Theframe 97 extends for substantially the full length of the row of tanks,and the cross members 99 correspond in number to the number of elevatorsor tanks provided.

The frame 97 is supported for sliding movement along the support 95, andin the forwardmost position shown in Figures 4 and 5 of the drawings,the cross members 99 assume positions atthe front sides of therespective elevators. These cross members are also positioned torespectively engage the front edges .of the article supporting trays 20on the respective elevators to advance the trays from one elevatortoward the next adjacent elevator.

The frame 97 is reciprocated by a pair of racks 100 respectively securedat opposite-sides of the frame and extending in the general direction oflength of the frame. The racks are also respectively engageable with apair of gears 101 mounted on a cross shaft 102 in the manner shown inFigure 7 of the drawings and connected to a driving unit 103.

Referring again to Figure 4 of the drawings, attention is called to thefact that the tanks 55 and 57 are spaced from each other a greaterdistance than the distance between the other tanks, and accordingly thecross members 99 associated with the elevators 61 and 62 are spaced fromeach other a distance greater than the distance between other crossmembers. By reason of the spacing of the cross members 99 shownin Figure4 of the drawings, the article supporting tray on thefirst elevator 61is transferred from this elevator to a position on the supportingsurface 104 at the rear side of the elevator 61, while the articlesupporting trays on the following elevators are actually transferredfrom one elevator to the other, upon rearward movement of the frame 97from its forwardmost position shown in Figure 4 of the drawings. Thisarrangement provides for a drainage station 105 between the elevators 61and 62. The draining station merely comprises a plate 106 supportedbelow the por tion 104 of the support 95 in a position to receive drainage from the articles removed from the first elevator 61, and the plateis inclined to direct the drainage back into the tank 55.

The power unit 103 is operated in timed relation to the fluid motors 66and 67 by any suitable control circuit not shown herein. It will sufficeto point out that the elevators are in their raised positions when thedevice 97 is moved rearwardly, and the device remains in itsrearwardmost position until the elevators are lowered into therespective tanks. At this time the device 97 may be returned or movedforwardly without interference between the cross members 99 and thearticle supporting trays 20 on the elevators. When the device 97 ismoved forwardly, the article supporting tray at the drainage station 105is merely shifted forwardly by the adjacent cross member 99, and remainsin this position until it is advanced by the preceding tray on theelevator 61 to a position on the elevator 62. This action of coursetakes place when the device is again moved rearwardly after theelevators are raised to their uppermost positions.

Operation The power unit 51 for the racks 48 at the delivery end of thefurnace 21 is operated in timed relation to the power unit 103, and intimed relation to the fluid motors 28 by a control circuit which formsno part of the present invention, and is not disclosed herein. This isalso true of the operation of the fluid motors 40 for the dogs 43, 44and 46. It will suflice to point out that after the heating cycle, thedoors 25 and 27 are raised, and the racks 48 are operated to move thearticle trays 20 at the delivery end 26 of the furnaceto the positions53. At the same time the fluid motors 40 are operated to advance trays20 into the entrant end 24 of the furnace. The doors 25 and 27 are thenclosed, and the next heating cycle is started.

. cross members to the next adajacent elevator.

As the racks 48 move rearwardly to withdraw trays from the delivery endof the furnace, the dogs 54 transfer trays from the position 53 to theelevator 61. Prior to movement of the racks 48 rearwardly, thepropelling device 97 is moved to its rearwardmost position wherein thecross members 99 are positioned at the rear sides of the elevators. Itwill be understood that during the rearward movement of the device 97,the trays 20 on the elevator 61 are advanced to a position on theportion 104 of the support 95, and the trays previously deposited on theportion 104 are advanced by the preceding tray to a position on theelevator 62. p Also the trays formerly on the elevators 62, 63 and 64are advanced by the adjacent The trays on the last elevator 65 areadvanced by theuadjacent cross mcmber99 onto a delivery platform 106.

It follows from the above that when the trays 20 are advanced by thedogs 54 to positions on the elevator 61,

i the following elevators also have trays thereon. As soon as trays 20are transferred from the position 53 to the elevator 61, all of theelevators are lowered into their respective tanks. The articlessupported by the trays on the elevator 61 are at elevated temperaturesdue to the heat treating operation accomplished in the furnace 61, andaccordingly, need be retained in the alkali bath for only a relativelyshort length of time.

Prior to movement of the elevators to their raised positions, the device97 is moved forwardly by the power unit 103 to again locate the crossmembers 99 to positions in advance of the adjacent elevators. After thedevice 97 is moved to its forwardmost position, the elevators are raisedby the fluid motors 66 and 67.

As soon as the elevators assume their uppermost positions, the device 97is again moved rearwardly to transfer the trays from the elevator 61 toa position on the portion 104. The trays on the remaining elevators aresuccessively advanced by the adjacent cross members 88 to the nextadjacent elevator, and the trays on the elevator 65 are deposited on thedelivery platform 106. It is pointed out at this time that as the traysare transferred from the elevator 61 to the portion 104 of the support95, these trays engage the trays previously deposited on the support,and advance the latter trays to positions on the elevator 62.

It follows from the above that the cleaning unit 22 operates inconjunction with the furnace 21 in a manner such that the heat treatingand cleaning operations are continuous. It will also be understood thatthe articles are at elevated temperatures when submerged into the alkalibath in the tank 55, so that this bath is not relied upon to heat thearticles. As a consequence, the articles need be retained in the bathonly a relatively short period, and this is desirable in that it reducesthe time required for the cleaning cycle to a minimum.

What I claim as my invention is:

1. Apparatus for treating articles, comprising a plurality ofreceptacles spaced from each other in a for Wardly and rearwardlyextending row and open at the top and each containing a bath, elevatorsrespectively supported for downward and upward movement as a unit intoand out of the baths through the open tops of the receptacles and havinggenerally co-planar article supporting surfaces, a support for thearticles positioned above the receptacles and having portions betweenthe elevators providing continuations of the article supporting surfacesof the elevators in the raised positions of the elevators, means formoving the articles rearwardly from one elevator to another insuccession comprising an article propelling device supported above thesupport for sliding movement in forward and rearward dircctions alongthe row of receptacles, said device having laterally spaced barsextending along the rows of receptacles and longitudinally spacedmembers connecting said bars respectively positioned at the front sidesof the elevators, means for moving the device in a rearward directionalong the row of receptacles in the raised positions of the elevators tomove articles by said members from said article supporting surfaces in arearward direction and for moving the device in a forward direction in alowered position of the elevators to return the members to theirpositions at the front sides of the elevators.

2. The apparatus set forth in claim 1 in which the spacing between twoadjacent elevators and the stroke of the propelling device is such thatthe articles are successively moved rearwardly from one of said adjacentelevators to the other across the intervening portion of said supportupon each rearward stroke of the propelling device.

3. The apparatus set forth in claim 1 in which the spacing between twoadjacent elevators exceeds the stroke of the propelling device totransfer articles from the supporting surface of the forwardmost of saidadjacent elevators onto the portion of the support between said twoadjacent elevators, and in which means is provided for returningdrainage from the articles deposited on the last-mentioned portion ofthe support back into the preceding receptacle.

4. Apparatus for treating articles comprising a receptable containing abath and open at the top, an elevator supported for downward and upwardmovement into and out of the bath through the open top of the receptacleand having an article supporting surface, an article support havingportions extending rearwardly from the rear side of the path of travelof the elevator and forming a continuation of the article supportingsurface of the elevator in the raised position of the latter, an articlepropelling member supported above the support for forward and rearwardmovement across the article supporting surface of the elevator, meansfor moving the member rearwardly from a position at the front side ofthe elevator across the article supporting surface of the elevator inthe raised position of the latter to move an article from said articlesupporting surface rearwardly onto the support and for returning themember to the front side of the elevator when the latter is in aposition below the support, and means associated with the support forconveying drainage from the article on the support into said bath.

References Cited in the file of this patent UNITED STATES PATENTS294,441 Chess Mar. 4, 1884 586,858 Mesta July 20, 1897 1,959,215 OwenMay 15, 1934 2,223,603 Darrah Dec. 3, 1940 2,248,732 Albrecht et a1.July 8, 1941 2,254,913 Roth Sept. 2, 1941 2,477,561 Holden Aug. 2, 19492,633,855 Ransoholf Apr. 7, 1953 2,639,047 Ipsen May 19, 1953 2,654,462Todd Oct. 6, 1953 FOREIGN PATENTS 616,151 Great Britain Ian. 17, 1949

